Photographic images that allow recreation or approximation of the natural hues of a subject are conventionally captured on photographic film mounted in a camera. Camera speed films typically employ high bromide silver halide emulsions. Separate images of each of blue, green and red exposures arc captured in blue, green and red recording layer units within the film. The blue recording layer unit contains chemically sensitized high bromide grains that may rely on native blue sensitivity or be sensitized to the blue region of the spectrum with one or more blue absorbing spectral sensitizing dyes. The green recording layer unit contains chemically sensitized high bromide grains that are sensitized to the green region of the spectrum with one or more green absorbing spectral sensitizing dyes. The red recording layer unit contains chemically sensitized high bromide grains that are sensitized to the red region of the spectrum with one or more red absorbing spectral sensitizing dyes. Dye-forming couplers are typically included in the layer units to allow dye images of distinguishable hue to be formed upon color processing. When the photographic film is intended for reversal processing to produce a viewable color positive image or when the photographic film is intended for use in exposing a color paper, the blue, green and red recording layer units contain couplers that form blue absorbing (yellow), green absorbing (magenta), and red absorbing (cyan) image dyes, respectively. When the dye image information is intended to be retrieved from the photographic film by digital scanning, the dye images can be of any hue, provided they are distinguishable.
The components used to construct color photographic films are disclosed in Research Disclosure, Vol. 389, September 1996, Item 38957. Research Disclosure is published by Kenneth Mason Publications, Ltd., Dudley House, 12 North St., Emsworth, Hampshire P010 7DQ, England. The following topics of Item 38957 are particularly pertinent to the present invention:
I. Emulsion grains and their preparation PA1 II. Vehicles, vehicle extenders, vehicle-like addenda and vehicle related addenda; PA1 IV. Chemical sensitization; PA1 V. Spectral sensitization and desensitization PA1 X. Dye image formers and modifiers PA1 XI. Layers and layer arrangements; PA1 XII. Features applicable only to color negative; PA1 XIII. Features applicable only to color positive PA1 XV. Supports. PA1 Daubendiek et al U.S. Pat. No. 4,414,310; PA1 Abbott et al U.S. Pat. No. 4,425,426; PA1 Wilgus et al U.S. Pat. No. 4,434,226; PA1 Maskasky U.S. Pat. No. 4,435,501; PA1 Kofron et al U.S. Pat. No. 4,439,520; PA1 Solberg et al U.S. Pat. No. 4,433,048; PA1 Evans et al U.S. Pat. No. 4,504,570; PA1 Yamada et al U.S. Pat. No. 4,647,528; PA1 Daubendiek et al U.S. Pat. No. 4,672,027; PA1 Daubendiek et al U.S. Pat. No. 4,693,964; PA1 Sugimoto et al U.S. Pat. No. 4,665,012; PA1 Daubenidiek et al U.S. Pat. No. 4,672,027; PA1 Yamada et al U.S. Pat. No. 4,679,745; PA1 Daubendiek et al U.S. Pat. No. 4,693,964; PA1 Maskasky U.S. Pat. No. 4,713,320; PA1 Nottorf U.S. Pat. No. 4,722,886; PA1 Sugimoto U.S. Pat. No. 4,755,456; PA1 Goda U.S. Pat. No. 4,775,617; PA1 Saitou et al U.S. Pat. No. 4,797,354; PA1 Ellis U.S. Pat. No. 4,801,522; PA1 Ikeda et al U.S. Pat. No. 4,806,461; PA1 Ohashi et al U.S. Pat. No. 4,835,095; PA1 Makino et al U.S. Pat. No. 4,835,322; PA1 Daubendiek et al U.S. Pat. No. 4,914,014; PA1 Aida et al U.S. Pat. No. 4,962,015; PA1 Ikeda et al U.S. Pat. No. 4,985,350; PA1 Piggin et al U.S. Pat. No. 5,061,609; PA1 Piggin et al U.S. Pat. No. 5,061,616; PA1 Tsaur et al U.S. Pat. No. 5,147,771; PA1 Tsaur et al U.S. Pat. No. 5,147,772; PA1 Tsaur et al U.S. Pat. No. 5,147,773; PA1 Tsaur et al U.S. Pat. No. 5,171,659; PA1 Tsaur et al U.S. Pat. No. 5,210,013; PA1 Antoniades et al U.S. Pat. No. 5,250,403; PA1 Kim et al U.S. Pat. No. 5,272,048; PA1 Delton U.S. Pat. No. 5,310,644; PA1 Chang et al U.S. Pat. No. 5,314,793; PA1 Sutton et al U.S. Pat. No. 5,334,469; PA1 Black et al U.S. Pat. No. 5,334,495; PA1 Chaffee et al U.S. Pat. No. 5,358,840; PA1 Delton U.S. Pat. No. 5,372,927; PA1 Daubendiek et al U.S. Pat. No. 5,576,168; PA1 Olm et al U.S. Pat. No. 5,576,171; PA1 Deaton et al U.S. Pat. No. 5,582,965; PA1 Maskasky U.S. Pat. No. 5,604,085; PA1 Reed et al U.S. Pat. No. 5,604,086; PA1 Eshelman et al U.S. Pat. No. 5,612,175; PA1 Levy et at U.S. Pat. No. 5,612,177; PA1 Wilson et al U.S. Pat. No. 5,614,358; PA1 Eshelman et al U.S. Pat. No. 5,614,359; PA1 Maskasky U.S. Pat. No. 5,620,840; PA1 Wen ct al U.S. Pat. No. 5,641,618; PA1 Irving et al U.S. Pat. No. 5,667,954; PA1 Maskasky U.S. Pat. No. 5,667,955; PA1 Maskasky U.S. Pat. No. 5,691,131; PA1 Maskasky U.S. Pat. No. 5,693,459; PA1 Black et a1 U.S. Pat. No. 5,709,988; PA1 Jagannathan et al U.S. Pat. No. 5,723,278; PA1 Deaton et al U.S. Pat. No. 5,726,007; PA1 Irving et al U.S. Pat. No. 5,728,515; PA1 Bryant et al U.S. Pat. No. 5,728,517; PA1 Maskasky U.S. Pat. No. 5,733,718; PA1 Jagannathan et al U.S. Pat. No. 5,736,312; PA1 Antoniades et al U.S. Pat. No. 5,750,326; PA1 Brust et al U.S. Pat. No. 5,763,151; and PA1 Maskasky et al U.S. Pat. No. 5,792,602.
(note most particularly the last sentence of paragraph (1) of B. Grain morphology); PA2 A. Sensitizing dyes; PA2 (except A. silver dye bleach); PA2 (except C. Color positives derived from color negatives);
Sutton et al U.S. Pat. No. 5,300,413 discloses high bromide {111} tabular grain emulsions with grain dispersitics and thicknesses controlled to facilitate blue light reflection.
Research Disclosure Item 38957, I., cited above, E. Blends, layers and performance categories, (7) discusses the common practice of dividing a recording layer unit into two, three or more emulsion layers differing in speed. Typically, when this is done, the emulsion layer of the highest sensitivity is coated to first receive exposing radiation, since this increases speed. Paragraph (7) also notes, "When a slower emulsion layer is coated over a faster emulsion, increased contrast is obtained."